Steam boiler and furnace



i April 30, .1935.

H. .J. KERR swam BOILER AND FURNACE Filed Sept. 9, 1927 2 Sheets-Sheet lINVENTOR ATTORNEYJ H. J. KERR STEAM BOILER AND FURNACE Filed Sept. 9,1927 2 Sheets-Sheet 2 April 30, 1935.

F i Z III INVENTOR I'ZQ. LIQU D HEATERS 1,

PORIZERS,

Patented Apr. 30, 1935 Search noun UNITED STATES PATENT OFFICE STEAMBOILER AND FURNACE Howard J. Kerr, Westfield, N. J., assignor to TheBabcock & Wilcox Company, Bayonne, N. .L, a corporation of New JerseyApplication September 9, 1927, Serial No. 218,416

11 Claims.

My present invention is particularly applicable to furnaces of the typeburning finely divided fuel, though it will be understood that myinvention is not limited to such use.

My invention will be best understood from the following description inconnection with the accompanying drawings illustrating one embodimentthereof, and in which Fig. 1 is a vertical section through a boiler andits setting, constructed according to my invention and taken on the lineI-I of Fig. 2; Fig. 2 is a partial plan view, and Fig. 3 is a sectiontaken on the line 3-3 of Fig. 1.

Like reference characters indicate like parts in the several views.

In the illustrative embodiment of my invention, a plurality of steam andwater drums ID are provided to each of which is connected a bank ofinclined water tubes I I connected at one end to downtake headers I2 andat their other end to uptake headers I3. The downtake headers I2 areconnected to the associated drum I0 by nipples I4, and the uptakeheaders I3 are similarly connected to the drum by nipples I5.

The front or uptake headers of the boiler are placed above therefractory front wall I! of the furnace chamber I8. Fuel burner nozzlesI9 enter the chamber I 8 and are supported in the front furnace wallI'I. Ash outlets 2D communicate through the front wall I! with thelowest portion of the interior furnace chamber. Side walls 2| (one ofwhich is illustrated in Fig. 2), a sloping floor 22, and a rear wall 23complete the enclosure of the furnace chamber. The rear wall 23 ispreferably joined to the floor 22 on a curve of relatively large radius,as illustrated at 23I A row of inclined slag screen tubes 24 crosses theupper portion of the furnace chamber I8 parallel with the tubes II andspaced therefrom.

The flame from the fuel nozzles I9 is deflected upwardly from the floor22 and forwardly from the rear wall 23. A baffle 25 extends from therear wall 23, along the slag screen tubes 24, and preferably supportedthereon to deflect the hot gases forwardly in the furnace chamber andtoward the front of the boiler tubes II. A baffle 26 extends upwardlyfrom the forward edge of the baffle 25 to direct the first upward flowof hot gases across the bank of boiler tubes II. A refractory wall 27and bafile 28 extend downwardly from the drums I0 across the majorportion of the boiler tubes II between the bafile 25 and the downtakeheaders I2. The baffle 28 and wall 21 direct the gases in a downwardpass over a soot pocket 29 formed between the bafiles 25 and 26 and thefurnace setting.

The soot pocket 29 constitutes an open space below the boiler tubes I Iwhere the gases make a turn and precipitate flue dust before makingtheir last upward pass over the boiler tubes. An access opening 30preferably communicates with the soot pocket. The flue gases passupwardly from the soot pocket and passing between the nipples I4 enterthe outlet flue 3| The floor 22 and rear wall 23 of the furnace chamberare relatively thin and are built upon and supported by water tubes 33comprising part of a secondary circulation system. The floor and wallare preferably relatively flexible to accommodate themselves to changes,due to temperature changes. The secondary cooling circulation isindependent of the main boiler circulation. A header 34 is connected toeach of the boiler drums II] by tubes 35. This connection is made to thelowest part of each boiler drum near its cooler end, adjacent thenipples to the downtake headers. The header 34 extends outwardly of thefurnace setting and is connected to a lower header box 36 by piping 31.The header box 36 is preferably in the plane of the floor tubes 33 whichare connected thereto. The floor and wall tubes 33 discharge at theirupper ends into a header 3B which, in turn, discharges into the tubes24. A header 39 outside the front wall receives the steam and water fromthe tubes 24 and returns it to the boiler drums through connecting tubes40 and 4|.

In the embodiment of my invention illustrated, two single boiler unitseach comprising two steam and water drums and the associated boilertubes and headers are illustrated, mounted over a single furnace.Separate headers 38 and 39 are provided for each boiler unit as shown inFig. 2. If desired, continuous headers may be used from side to side ofthe setting with partitions at their middle points in place of theseparate headers.

The tubes 40 are connected to the upper side of the header 39 and to thesteam space of one of the drums Ill. The tubes 4I enter the header 39along its side and discharge into the steam space of the adjacent boilerdrum III. In the secondary boiler circulation, water flows from thecooler parts of the drums II) to the lower header 36, thence through thecooling and supporting tubes 33 and the slag screen tubes 24 in seriesto the steam space of the boiler drums II]. This circulation provides aneffective protection for the furnace walls against injury from excessivetemperatures.

a special fioor construction which causes a rapid transfer of heat fromthe surface of the floor 22 to the cooling tubes which support it. Thespecial floor is made of blocks 43 which rest upon and fit between thewater tubes in the floor. The blocks 43 are preferably metallic and aremounted in intimate contact with the supporting tubes 33. Metal clamps44 are bolted to the floor blocks and to each other. The clamps 44intimately contact with the tubes and the blocks to' form a solidmetallic floor gripping the tubes. The blocks 43 preferably haverelatively small insets 45 of highly refractory material to protect theface of the metal from pitting and attrition by the action of the flameand hot slag particles. The insets 45, however, are each so small and sonearly completely surrounded by metal that they are kept comparativelycool as the heat is readily conducted from them through the metal to thewater tubes 33.

A heat insulating casing 46 furnishes a suitable exterior or forms afinished surface to the exterior of the furnace wall. The floor andvertical wall may be supported by girders 4'! at one point only, asshown, or at any suitable intervals as may be needed. This support willpermit movement of the floor and wall by flexure at the curve connectingthem.

In operation, a rapid circulation is maintained through the tubes 33 andthe slag screen tubes 24, due to the vigorous formation of steam inthem. The presence of a large proportion of steam in the tubescontaining the rising fluid causes a difference in the weight of thedowncoming and rising columns of liquid and sustains a rapid andvigorous circulation. The water cooled floor of the furnace can thus bemaintained at a temperature suitable for handling the slag which may beremoved in the solid state in a disintegrated form, or which may beallowed to fuse on the floor of the furnace and afterwards be melted offby increasing the temperature of the furnace.

The soot pocket 29 is very conveniently disposed at a place in thesystem where difficulty would otherwise occur, due to accumulations offlue dust. It forms a simple and conveniently accessible means oftrapping and holding flue It will be understood that the passageways 48under the floor and between the castings 44 and the casing 46 may beoccupied and cooled by circulating air, if desired, either to cool thefloor or to heat air for any desired purpose. It will also be understoodthat my invention is not limited to the specific details or uses hereinset forth, but changes therein may be made to suit the needs orparticular circumstances.

I claim:

1. A boiler comprising a steam and water drum and a furnace having acooling circulation comprising water tubes for the lining thereof andconnected to said boiler, said circulation including an upper header andconnections therefrom to the steam and water drum, a lower headerexteriorly placed adjacent a lower wall of the furnace, continuous watertubes connected to said lower header and supporting said floor and awall of the furnace, a third header to which said continuous tubes areconnected, and slag screen tubes connecting said third header to saidupper header.

2. In combination, a steam boiler comprising a bank of horizontallyinclined water tubes, a set- Referring more particularly to Fig. 3, Ishow ting for said boiler comprising a furnace chamber located belowsaid tubes, a Wall for said furnace chamber having a substantiallyvertical and a sloping portion, second water tubes located adjacent thesaid vertical and sloping portions, third water tubes extending belowsaid bank of water tubes substantially parallel therewith and spacedtherefrom and connected in series with said water tubes located adjacentthe said wall, and means for creating a circulation through said secondand third water tubes.

3. In combination, a steam boiler comprising a bank of horizontallyinclined first water tubes, a setting for said boiler enclosing afurnace chamber located below said tubes, a furnace wall for saidchamber comprising a sloping and a substantially vertical portion,second water tubes located in proximity to said wall for cooling thesame, a cross header to which the upper ends of said second tubes areconnected, third water tubes extending below said bank of water tubessubstantially parallel therewith and connected to said cross header, andmeans for creating a circulation through said first water tubes and a.

circulation through said second and third water tubes.

4. In combination, a boiler comprising an upper drum, a bank ofhorizontally inclined tubes, end headers connected to said drum and towhich the ends of the tubes of said bank are connected, a setting forsaid boiler enclosing a furnace chamber below said tubes, a furnace wallcomprising a sloping portion and a substantially vertical portion,second water tubes located in proximity to said wall for cooling thesame, third water tubes extending below said bank of water tubessubstantially parallel therewith and connected in series with saidsecond water tubes, and connections for creating a circulation throughsaid second and third water tubes.

5. A furnace having walls, fuel burners for said furnace, a floor forsaid furnace, continuous water tubes extending beneath said floor andadjacent to one of said walls, said tubes being bent between the fioorand said wall, said floor and said wall being supported only at portionsremoved from said bent portions of the tubes, whereby said wall and saidfloor are flexibly supported at the bent portions of the tubes, and slagscreen tubes traversing the upper portion of the furnace chamber, thetubes for said floor, wall and slag screen being connected in series.

6. In combination, a boiler comprising an upper drum, a bank ofhorizontally inclined tubes, end headers connected to said drum and towhich the ends of the tubes of said bank are connected, a setting forsaid boiler enclosing a furnace chamber below said tubes, a furnace wallcomprising a sloping portion and a substantially vertical portion,second water tubes located in proximity to said wall for cooling thesame, the sloping portion of said wall comprising a floor laid upon thetubes, third water tubes extending below said bank of water tubessubstantially parallel therewith and connected in series with saidsecond water tubes, and connections for creating a circulation throughsaid second and third water tubes.

7. In a furnace, a continuous wall closure for the bottom and one sidethereof and comprising upper and lower fixed headers external to thefurnace, a row of spaced water tubes connecting said headers and bent toform a sloping bottom and a substantially vertical side, members fillingthe spaces between said tubes, said wall being free I22. Ll'iiulivHEATERS P. vAnOR ZE S.

to expand between said fixed headers, and means for causing water toflow through said tubes.

8. In a furnace, a continuous wall closure for the bottom and one sidethereof and comprising upper and lower fixed headers external to thefurnace located on one side and near the bottom, respectively, of saidfurnace, a row of spaced water tubes connecting said headers and bent toform a sloping bottom and a substantially vertical side, members fillingthe spaces between said tubes, said wall being free to expand betweensaid fixed headers, means for causing water to flow through said tubes,and means for delivering a flame against said sloping bottom and saidvertical side.

9. In a steam boiler and its furnace, a continuous wall closure for thebottom and one side thereof and comprising upper and lower fixed headersexternal to the furnace, a row of spaced water tubes connecting saidheaders and bent to form a sloping bottom and a substantially verticalside, members filling the spaces between said tubes, said wall beingfree to expand between said fixed headers, a boiler drum, andconnections including slag screen tubes between the ends of said tubesand said boiler drum for completing the circulatory system.

Search lioom 10. In a furnace, a continuous wall for the bottom and oneside thereof, said wall comprising a row of spaced water tubes bent toform a sloping bottom and a substantially vertical side, members fillingthe spaces between said tubes, said wall being free to expand betweenits ends, means to supply water to said tubes, and means for deliveringa flame toward said sloping bottom and said vertical side.

11. In a furnace, wall cooling tubes forming an upright side wall and ahorizontally inclined bot-. tom portion of the combustion chamber of thefurnace, a header connected to the tubes at the lower end of the bottomportion, a header connected to the tubes at the top of the side wall, asupport for said last named header enabling it to support a part of theweight of the combined side wall and bottom portion, refractory meanscarried by the tubes for completing furnace closures across the tubes,the side wall and bottom portion formed by the tubes and refractoryextending at a substantial angle to each other and their adjacent partsmovable outwardly of the combustion chamber when the temperature of thetubes is increased.

HOWARD J. KERR.

